people not using logic is from all ages

I think 3DS successor in 2016 but they could wait while like they did with DS,but I think it will just make it to GBA sales when successor launch,but It will sell a few mill after that.

I just took a look at the gap charts to find that after 35 months, the DS had sold 52M and the 3DS 41M. At this point, the 3DS is at roughly 78% sales of the DS. If the 3DS follows the trend of the DS, the 3DS will have about 119M sales lifetime. I think that this is a stretch, but it certainly helps to support the argument of those who think the 3DS will top the GBA.

Depends on how you define "successor" because I think the next Nintendo portable will also be a hybrid/fusion console product with the 3DS existing alongside it for a few years.

That said right now I'd say

2014 - 12 million 3DS' sold
2015 - 10.5 million 3DS' sold
2016 - 9 million 3DS' sold

Seems like a reasonable assumption which brings Nintendo up to ... 73.5 million by the end of 2016. Looks like a no I guess.

The problem with this is that the DS took a while to take off. In the 12 months up to 35 months (so month 23 to 35), the DS sold 25 million, whereas the 3DS sold 14.

If that ratio sticks, the DS will sell 100 million from 35 months and out, whereas the 3DS will sell 56 million, which would put the 3DS at just shy of 100 million lifetime.

This does, however, assume that the 3DS will be Nintendo's primary handheld for as long as the DS was. The DS was for 6 years and 3 months, which would put the 3DS successor's release in June 2017. If the 3DS stays around that long, then certainly, around 100 million seems probable.

I think its likely to sell about 65 million in its lifetime. Maybe Nintendo is working on another model so maybe 70 million is possible. But yeah I just dont see it reaching GBA sales.

Though it really depends on if It manages to stay popular even after its successor is released or if it'll quickly drop like the Wii did.

You made good points.  

The length of its lifespan all depends on if Nintendo decides to make another psuedosuccessor like what the DSi was to the DS.

I doubt it.

Obviously we have hindsight now, but 2000-2010 was the absolute boom period of dedicated handhelds.

In the 1990s everyone but Nintendo failed to make an impact with a handheld. Even Nintendo essentially gave up on the GameBoy until years after it should have had a successor a game called Pokemon came out and kick started what would become this boom period.

We had two handhelds sell a combined 230 million units. That is insane and anyone who expected that to continue or grow had a very optimistic outlook. With phones such as iPhone allowing people to have cheap games on device they already owned we are now in a contraction or correction era depending on your view.

My best prediction.

The DS will forever stand as the single best selling dedicated handheld device. Why? Because that concept will likely no longer exist. Sony will very likely abandon the Vita leaving it as a niche product with Japanese third party support. Nintendo's next handheld will possibly go a few directions.

1. Combining their handheld and console into one machine
2. Making their handheld a phone hybrid

I think Nintendo can be viable because they still have the best stable of IPs in gaming and billions in reserve. That said, what ever follows the 3DS could be the last if their system is rejected by the market (sells less than 50 million WW).

Man, I can't believe there's already serious talk of a successor and losing LTD to the GBA/PSP of all things.

Guess mobile really did do a number on the handheld scene.